Nickel-Cadmium, commonly known as the Ni-Cd battery, is one of the oldest rechargeable battery technologies. Although it was widely used for many decades, it has now been largely replaced by newer battery chemistries such as Nickel-Metal Hydride (NiMH) and Lithium-Ion (Li-ion).
Lesson Locked
We keep this course completely free by showing one short sponsored video before playback.
Even today, however, Ni-Cd batteries are still used in some specialized applications because of their durability and ability to deliver high currents.
Where are Ni-Cd batteries used?
Ni-Cd batteries are commonly available as 1.2 V rechargeable cells and were once widely used in:
- Flashlights
- RC toys
- Cordless power tools
- Emergency lighting
- Portable electronic devices
They can typically be charged and discharged hundreds of times, and with proper care, they can last for many years.
Advantages of Ni-Cd batteries
Ni-Cd batteries have several advantages that made them popular for a long time.
They are relatively inexpensive, have a long shelf life, and can deliver high currents when needed. They also perform well over a wide range of temperatures and are known for their rugged construction.
These characteristics make them suitable for applications that require reliability and frequent charging.
Memory effect
One of the biggest disadvantages of Ni-Cd batteries is a phenomenon known as the memory effect.
If a Ni-Cd battery is repeatedly recharged after only partial discharge, it may gradually appear to “remember” the shorter discharge cycle. As a result, the battery may deliver less usable capacity before its voltage drops.
Although the memory effect is often overstated and occurs only under certain operating conditions, it was one of the reasons newer battery technologies became more popular.
Environmental concerns
Another major drawback of Ni-Cd batteries is that they contain cadmium, which is a toxic heavy metal.
If these batteries are not disposed of properly, cadmium can contaminate soil and water, posing risks to both the environment and human health.
For this reason, the use of Ni-Cd batteries has been restricted in many countries, and they should always be recycled through proper battery recycling programs.
Why were Ni-Cd batteries replaced?
Over time, Ni-Cd batteries were gradually replaced by Nickel-Metal Hydride (NiMH) and Lithium-Ion (Li-ion) batteries.
These newer battery technologies offer higher energy density, are more environmentally friendly, and do not suffer from the same level of memory effect. As a result, they have become the preferred choice for most modern portable electronic devices.